HP 8560A, Руководство по обслуживанию

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6. Sampling Oscillator Adjustment
Procedure
1. Set the HP 8560A switch to off and disconnect the line power cord. Remove the
analyzer cover and fold down the Al5 RF and Al4 Frequency Control assemblies. Prop
up the Al4 Frequency Control assembly. Reconnect the line power cord and set the (LINE)
switch on. Connect the equipment as illustrated in Figure 2-8.
2. Press on the HP 8560A and set the controls as follows:
CENTER FREQ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . MHz
CF STEP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...30 MHz
SPAN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 Hz
3. Set the HP 3456A controls as follows:
FUNCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DCVOLTS
RANGE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..lOV.MANUAL
Phase Detector Bias Adjustment
4. Connect the negative DVM lead to pin 6, and the positive lead to pin
5. Adjust PHASE DET BIAS for a DVM reading of f0.02 Vdc.
Sampling Oscillator Fine-Tune Adjustment
6. Connect the positive DVM lead to pin 13. Leave the negative DVM lead
connected to pin 6.
7. Adjust VCO RANGE for a DVM reading of Vdc.
Note If cannot be adjusted for 5.18 Vdc, perform the coarse-tune
adjustment located at the end of this procedure.
Power and Sampler Match Adjustments
8. Connect the negative DVM test lead to pin 6, and the positive DVM test lead to
pin 1.
9. Press and set the HP 8560A center frequency to 511 MHz. This sets the
sampling oscillator to 288 MHz.
10. Adjust SMPL MATCH 1 to peak the voltage displayed on the DVM.
Note
If a peak cannot be obtained, the sampling oscillator power might be too low.
Adjust
SMPL PWR ADJ clockwise one-eighth turn and repeat step
10. If necessary, continue increasing the oscillator power, but do not allow the
displayed voltage to exceed Vdc when peaked.
11. Adjust SMPL PWR ADJ to set the displayed voltage to f0.2 Vdc.
2-34 Adjustment Procedures